Time division multiplex system and method having a time slot reuse capability

A time division multiplex (TDM) communication system including a communication channel and a plurality of stations connected to said channel, said system including

• means for generating and propagating time slots to said stations sequentially, said time slots being initially marked as "empty,"
• means in each station for placing a designation station address and data intended for a destination station in an individual time slot marked as "empty" and for re-marking that time slot as "busy",
• means in each station for marking as "used" each time slot propagated thereto which has that station as its destination, and
• a single means dedicated to at least two predetermined stations of said plurality of stations and connected to said channel for re-marking as "empty" each time slot marked as "used" by a station not at the location of said single means.

Apparatus for use in a time division multiplex (TDM) communication system and arranged to receive and transmit information in a first and a second time interval, said apparatus comprising

• means for determining if received information in said first time interval identifies said apparatus as a destination for said received information,
• means responsive to a first result of said determining means for transmitting control information having a first value in said second time interval,
• first means for detecting a beginning of message identifier in said received information,
• first enabling means jointly responsive to said first result from said determining means and to the detection of said beginning of message identifier for enabling said message identifier and data of said received information to be stored by said apparatus,
• second means for detecting a message continuation identifier in said received information,
• means for comparing a received message identifier against a previously stored message identifier, and
• second enabling means jointly responsive to the detection of said message continuation identifier and to a first indication from said comparing means indicating that said received message identifier is equal to said stored message identifier for enabling said received information to be stored by said apparatus.

A method of operating apparatus used in a time division multiplex (TDM) communication system and arranged to receive and transmit information in a first and a second time interval, said method comprising the steps of

• determining if received information in said first time interval identifies said apparatus as a destination for said received information
• transmitting control information having a first value in said second time interval in response to a first result obtained during said determining step, and
• detecting a beginning of message identifier in said received information,
• enabling, jointly in response to said first result from the determining step and the detection of said beginning of message identifier, said message identifier and data of said received information to be stored by said apparatus,
• detecting a message continuation identifier in said received information,
• comparing a received message identifier against a previously stored message identifier, and
• indicating, jointly in response to the detection of said message continuation identifier and to a first indication from said comparing means, that said receive message identifier is equal to the stored message identifier for enabling said received information to be stored by said apparatus.

A method of operating a time division multiplex TDM communication system including a communication channel with an erasure node dedicated to a plurality of stations connected thereto, said erasure node and each of said plurality of stations arranged to receive and transmit information in a first and a second time interval of said channel, said method comprising the steps of

• at least two of said plurality of stations
• determining, in response to received information including busy control information and an address in said first time interval, if said address in said first time interval identifies said station as a destination station for said received information and
• transmitting over said channel a slot read control status signal having a first value in said second time interval in response to a first result obtained during said determining step;
• and
• at said erasure node, detecting said slot read control status signal in said second time interval, and
• erasing said busy control information in said first time interval in response to a first status signal value of said slot read control information obtained from a station not at the location of said erasure node.